Final answer:
Competition between two species occurs when they overlap niches, leading to interspecific competition. This scenario can result in the extinction of the less adapted species due to conflict over limited resources like food or nesting spaces.
Step-by-step explanation:
Competition between two species occurs when there is an overlap in their niches. A niche includes all of the factors that a species needs to survive, grow, and reproduce. When two species have similar requirements for resources, and these resources are limited, interspecific competition ensues, which can lead to the decline or extinction of the less adapted species. This competition can manifest in a competition for food, nesting space, or any other resource that both species rely upon for survival.
For example, if two bird species compete for the same type of seeds in a limited geographic area, they will struggle against each other to access this food resource. Interspecific competition is a fundamental mechanism of evolution, influencing the distribution and population size of the competing species. According to the Competitive Exclusion Principle, no two species can sustain the same niche in the same environment indefinitely; therefore, one species will either go extinct, migrate to a different area, or adapt through evolutionary changes in its niche preferences.